tell tales
/ˌtel ˈteɪlz/idiom
to tell someone in authority about another person’s bad behaviour
ябедничать, доносить
Русский аналог: «ябедничать»
Чаще о детях. Tell-tale — ябеда.
“Don’t tell tales about your brother.”
“Nobody likes a child who tells tales.”
“He was accused of telling tales to the boss.”